The present invention relates generally to golf clubs, and is particularly concerned with a golf club head having an internal cavity which is partially or completely filled.
It is known to provide various filler materials in the cavities of golf club heads for weighting and vibration damping purposes. In U.S. Pat. No. 4,438,931 of Motomiya, the head is filled with an elastic filler material such as foamed urethane and rubber. In U.S. Pat. No. 5,649,873 of Fuller, for example, a layer of cork particles and bonding material is adhered to the inner surface of the club head cavity. However, glued cork particles are relatively heavy and not particularly durable, given the wear and tear that occurs as a result of being compressed and de-compressed with repeated impacts of the head with a ball.
It is an object of the present invention to provide a new and improved golf club head with a filled cavity.
According to one aspect of the present invention, a golf club head is provided which comprises a hollow body having a front, striking face, a rear face, an upper face, a heel and a toe, and an open lower end, and a sole plate extending over the lower end of the body, the body having an internal cavity of predetermined shape and dimensions, and at least one piece of solid cork or synthetic cork material cut to match the shape and dimensions of at least part of the cavity, the solid cork piece being positioned in said cavity.
In an exemplary embodiment of the invention, two pieces of solid cork material are cut to match the shape and dimensions of different parts of the cavity, and, when positioned in the cavity, substantially fill the entire cavity. In another embodiment, one or more solid cork pieces partially fill the cavity, and the remainder of the cavity is filled with a foam filler material. In the latter case, the solid cork pieces fill at least 50% of the total internal volume of the cavity.
The solid cork or synthetic cork material filling or partially filling the cavity will give a better feel and more consistent transfer of energy than a golf club head filled with other materials, such as foam filler material or glued cork particles. It will also be more durable than glued cork particles on repeated use of the club head.